Many factors, including environmental responsibility efforts and modern environmental regulations on engine exhaust emissions have reduced the allowable acceptable levels of certain pollutants that enter the atmosphere following the combustion of fossil fuels. Increasingly more stringent emission standards require greater control over both the combustion of fuel within the engine, and may require post combustion treatment of the exhaust. For example, the allowable levels of nitrogen oxides (NOX) and particulate matter have been greatly reduced over the last several years. To address, among other issues, environmental concerns, many diesel engines now have an exhaust particulate filter within an exhaust system of the engine purposed to reduce the amount of particulate matter released into the atmosphere.
In order to increase the service life of the exhaust particulate filter, an engine may be instructed by an engine control module to perform a regeneration cycle for the exhaust particulate filter that causes exhaust gas temperatures to rise to a level to regenerate the exhaust particulate filter by burning away trapped particulate matter. The regeneration cycle requires temperatures at the inlet of a diesel oxidation catalyst be at least a minimum temperature for proper regeneration of the exhaust gas particulate filter to avoid damaging the exhaust gas particulate filter. The minimum temperature at the diesel oxidation catalyst is required to ensure mixing and ignition of hydrocarbons injected for regeneration. In addition to requiring certain temperature conditions, the regeneration of the exhaust gas particulate filter also requires that the exhaust gas have a minimum mass flow rate in order to achieve proper regeneration. The exhaust particulate filter may require regeneration while the vehicle is stationary for many reasons, such as, the engine with the exhaust gas particulate filter in need of regeneration is subjected mainly to light loading conditions, the ambient temperature is low, aftertreatment parts have deteriorated based upon use, the engine is operating at speeds where air flow through the engine is low. Obtaining proper temperature and exhaust flow conditions for stationary regeneration of the exhaust gas particulate filter may be difficult to obtain.
Therefore a need exists for a method of performing stationary regeneration of an engine exhaust gas particulate filter that provides suitable conditions for regeneration.